Safety-key for drilling-rigs



E. J. GRIFFITH.

SAFETY KEY FOR DRILLING RIGS.

APPLICATION FILED JUNE 1. I920.

1,397,864, Patented Nov. 22, 1921.

Evan i Griffith E. J. GRIFFITH.

SAFETY KEY FOR DRILLING RIGS.

APPLICATION FILED JUNE 1, I920.

1 97,864, Patented Nov. 22, 1921.

2 SHEETSSHEET 2.

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vwewfoz Ev an- J Griffith UNITED STATES PATENT OFFICE.

EVAN J. GRIFFITH, 0F RIVERTON, WYOMING.

SAFETY-KEY FOR DRILLING-R108.

To all whom it mag 00mm Be it known that I, EVAN J. GRIFFITH, a citizen of the United States, residing at Riverton, in the county of Fremont and State of Wyoming, have invented certain new and useful Improvements in Safety- Keys for Drilling-Rigs, of which the following is a specification.

This invention relates to safety keys for pitman rods, and the primary object of the invention is to provide an improved means for operatively connecting the pitman rod of a drilling rig to the crank pin of a drive shaft, which will permit the quick and easy removal of the crank pin from the pitman rod when desired.

In drilling rigs now in vogue, a sliding wedge is usedfor holding the connecting block carried by the pitman rod in adjusted position in engagement with the crank pin of a drive shaft, but this has been found to be impractical owing to the fact that the wedge gradually slips out of place and considerable damage often results. It is therefore another object of the invention to eliminate the use of the wedge and thus prevent the inconveniences associated therewith and to provide means which will effectively hold the pitman in place on the crank pin without any lateral movement of the pitman and at the same time allow the crank pin to be quickly removed from the pitman when desired, without the use of tools.

A further object of the invention is to provide an improved means for operating the sliding block carried by the pitman so as to permit the same to be quickly moved into or out of engagement with a crank pin and to provide means for locking the block against movement in connection with the crank pin .or out of engagement with the crank pin.

A further object of the invention is to provide means for adjustably connecting the operating means with the sliding block so as to permit various sized crank pins to be used with the pitman rods.

A still further object of the invention is to provide an improved safety key for the pitman rods of drilling rigs, which is exceptionally durable and eflicient in use, one

. that is easy to manufacture, and one which can be placed upon the market at a reasonable cost.

With these and other objects in view, the invention consists in the novel construction, arrangement and formation of parts as will Specification of Letters Patent.

Application filed June 1,

Patented Nov. 22,1921.

1920. Serial No. 385,727.

be hereinafter more specifically described; claimed and illustrated in theaccompanying draw ngs, forming a part of this specification, in which drawings: I

Figure 1 is a fragmentary? side elevation of a drilling rig showing the improved safety-key applied thereto.

Fig. 2 1s a side elevation of a pitman rod and crank used in drilling rigs with the improved safety key applied thereto.

F g. 3 is a plan view of the same.

Fig. 4 is a bottom plan view of the same.

Fig, 5 is an enlarged fragmentary side elevatlon of, a pitman rod showing the improved safety key applied thereto, parts of the safety key and pitman rod being shown 1n section.

Fig. 6 is an enlarged detail sectional view through the operating means for the slidlng block showing the means for releasably holding the operating means against accidental movement.

Fig. 7 is an enlarged fragmentary sectional view through the operating means showing a modified form of lock for holdmg the operating means against movement.

Referring to I the drawings in detail, wherein similar reference characters designate corresponding parts throughout the several views, the letter A generally indicates the improved safety key for connecting the pitman rod B of a drilling rig C to the crank pin D of a prime mover E.

The drilling rig C may be of the usual or any preferred construction and as shown includes the drill operating lever F which is pivoted intermediate its ends upon a support G. The outer end of the operating lever F is connected to the pitman rod B by means of a stirrup H. The stirrup H is bolted or otherwise secured to the upper end of the pitman rod B and is detachably connected to the operating lever F by suitable removable bearing plates I.

The prime mover E may be of any desired type such as a gas or steam engine and includes the drive shaft J, and a crank arm K which carries the crank pin D.

The removable safety key A includes a pair of channel bracket plates 10 and 11, which are bolted or otherwise secured to the opposite sides of the pitman rod B which may be made of any preferred material such as wood or the like. The pitman rod B directly below the brackets 10 and 11 is provided with a longitudinally extending slot the lever in its adjusted position. Thelever" 12 which receives the sliding block 13 which is provided with a concaved face 14 for engaging the crank pin D. As clearly shown in Fig. 4 of the drawings, the crank pin D is positioned in the slot 12 and the lower.

will be hereinafter more fully described.

The bracket 10 carries an outwardly extending car 17 which slidably receives the threaded terminal of an adjusting rod 18, which is pivotally connected to one end ofthe cross lever 16 as at 19. The threaded terminal of the adjusting rod 18 has threaded thereon at opposite sides of the ear 17 the nuts 20 which form means for adjusting the lever 16 in relation to the ear 17 The channel bracket plate 11 carries outwardly extending spaced ears 21 which are arranged substantially at right angles to the car 17 and rotatably support an operatingshaft 22 and these ears 21 receive between themselves the adjusting cam 23 which is keyed or otherwise secured to the shaft 22. The cam 23 rotatably receives a cam strap 23, which carries'athreaded socket 25 for receiving the rod 26 which has its end oppositely threaded. One end of the rod 26 is connected to the terminal of the lever 16 the lugs 21 and the same has secured thereto an operating lever 28 the hub of which carries a spring pressed-catch 29 which is adapted to fit in any' one of a plurality of 'openings 3O formed in the outer surface of one'of thelugs 21. Thus it can be seen that when the lever 28 is operated, the lever 16 will-be swung on the connecting member 19 through the medium of the cam 23 and cam strap 23. and by connecting the lever with the block 13 the same can by readily and easily moved and brought into or out of engagement with the crank pin D. The spring pressed catch 29 forms means for holding 16 intermediate'its ends is provided with a depending block 31 which may be pivotally connected directly to the sliding block 13 or if desired yoke'32 is pivotally connected to the block 31 and the same has adjustably secured thereto an eye 33, which is pivotally secured as at 34 to the sliding block 13.

To effectively prevent-any lateral movementof the pitman rod B on the crank pin Dya plate 35 is bolted or otherwise secured to one face of the sliding block 13 and the lower-edge of this plate extends beyond the block 13 and is adapted to engage in an an nular groove 36 formed in the crank pin. The provision of this plate absolutely prevents any movement of the crank pin or piston rod in relation to each other.

The improved safety key is so constructed that the same can be. quickly removed from the pitman rod when desired, so that in case of an accident, the usual wedge can be substituted therefor for driving the sliding block into engagement with the crank pin.

It is to be understood that other means for holding the operating lever 28 in its adjusted position'may be used and as clearly shown in Fig. 7 of the drawings, an inwardly extending pinr37 is adapted to fit in any one of a series of substantially semicircular openings 38 formed'in one of the lugs 21 and this pin 37 is normally held in engagement with'any one of the sockets 38 by means of; an expansion spring 39 which is coiled around the shaft 22, which in this instance is extended beyond the ears 21. The spring 39 is held in place by means'of an adjusting nut 40 which is threaded on the shaft 22 and this nut also forms means for adjusting the tension of the spring.

In operation of the improved safety key, the block 13 is lifted by the'lever 16 to the desired position and the rods 18 and 26 are adjusted so that the block 12 and the plate 35 will firmly engage the crank pin D when the operating lever 28 is swung to'its lowermost position. When it is desired to move the pitman rod'from the crank pinyor insert new block in thepitman rod it is merely necessary to move the operating lever 28 so as to swing the cam 23 which will'effectively move the block out of engagement with the crank pin as clearly shown in Fig. 5 of the drawing. From the foregoing description it can be seen that an improved means is provided for effectively connecting the pitman rod of drilling rigs to a crank pin of a drive shaft which willeifectively hold the pitman rod in correct position and permit the same to be readily and quickly removed when desired or necessary.

Changes in detailsmay be made without departing from the spirit or scope of the invention; but,

I claim; V j 1. The combination with anengine drive shaftincluding a crank pin, of a pitman rod having a longitudinally extending slot therein arranged to receive the crank pin, a block slidably mounted in the longitudinally extending slot. a cross lever pivotally connected to said block, bearing brackets secured to the opposite sides of the pitman,

means adjustably connecting the cross lever with the bearing brackets, and an operating and away from said pin.

2. The combination with an engine shaft including a. crank pin having an annular groove formed therein, of a pitman rod having a longitudinally extending slot and a transversely extending slot, the crank pin being fitted in said longitudinally extending slot, a sliding block, mounted in said longitudinally extending slot and arranged to engage said crank pin, a plate carried by the block and extended beyond one end thereof arranged to engage in the annular groove formed in the crank pin when the block is moved into engagement with the crank pin and an operating lever for moving said block toward and away from said crank pin.

The combination with an engine drive shaft including a crank pin, of a pitman rod having a longitudinally extending slot and a transversely extending slot, the longitudinally extending slot being arranged to receixe the crank pin, a block slidably mounted in the longitudinally extending slot arranged to engage the crank pin, a cross lever slidably mounted in the transversely extending slot, means pivotally connecting the transversely extending lever with the sliding block, bearing brackets secured to the opposite side of the pitman rod, means adjustably connecting one end of the cross lever with one of the bearing brackets, a shaft rotatably carried by the other bearing bracket, means adjustably connecting the shaft with the other end of the cross lever, a cam carried by the shaft, operatively connected to said means for adjustably connecting the shaft with the cross lever, and means for rotating said shaft.

4. The combination with an engine drive shaft including a crank pin, of a pitman rod having a longitudinally extending slot and a transverse slot, the longitudinally extending slot being arranged to receivethe crank pin, a block slidably mounted in the longitudinally extending slot arranged to engage the crank pin, a cross lever slidably mounted in said transverse slot, means adjustably and pivotally connecting the transversely extending lever to the block, a pair of bearing brackets secured to the opposite faces of the pitman rod, means adjustably and pivotally connecting one end of the cross lever to one of the bearing brackets, a rotatable shaft carried by the other bearing bracket, a cam carried by said shaft, a strap mounted upon said cam, means adjustably and pivotally connecting said strap to the opposite end of said cross lever, and an operating lever carried by said shaft.

5. The combination with an engine drive shaft including a crank pin, of a pitman rod having a longitudinally extending slot and a transversely extending slot, the longitudinally extending slot being arranged to receive the crank pin, a block slidably mounted in the longitudinally extending slot arranged to be moved toward and away from said crank pin, a cross lever mounted in said transversely extending slot, means pivotally and adjustably connecting said cross lever to said sliding block, means carried by the sliding block to revent relative lateral movement on the pitman rod and crank pin in relation to each other, a pair of bearing brackets secured to the opposite faces of the pitman rod, an outwardly extending ear formed on one of the bearing brackets, a rod pivotally carried by one end of the cross lever, means adjustably connecting the ear with the rod, a shaft rotatably carried by the other bearing bracket, a cam mounted on said shaft, a cam strap surrounding said cam, a socket carried by said cam strap, a rod pivotally carried by the opposite end of the cross lever and adjustably connected to said socket, an operating lever secured to the shaft, a spring means for normally holding the operating lever against accidental movement.

EVAN J. GRIFFITH. 

